Journal of Agricultural Science and Sustainable Production
Year:2011 | Volume:21/2 | Issue:1|Papers Count:14

In order to evaluate intercropping of maize (Zea mays L.) and faba bean (Vicia faba L.), a field experiment was conducted as factorial on the bases of randomized complete block design with three replications. Treatments were intercropped combinations of maize densities (6, 7 and 8 plant/ m2) and faba bean densities (30, 40 and 50 plant/ m2) and 6 sole-cropped treatments. Two species intercropped as additive series. Results revealed that the effects of maize density were significant on ear length, number of seed rows per ear, seeds per row and seeds per ear, grain yield of maize and biological yield of maize. The faba bean density significantly affected all measured traits of maize except the number of seed row per ear and 100- maize kernel weight. The grain and biological yields of maize were significantly affected by interaction of maize and faba bean density. In monocropping, grain yield of maize increased, with increasing maize density at plant per square meter. The grain and biological yields of maize in intercropping were higher than those in mono cropping. However, plant density had not significant effect on grain and biological yields in intercropping. Intercropping rate of 6 maize and 30 faba-bean plants is introduced as advantageous system.

According to FAO statistics of the one-third of the world population still are envisaging with food deficiency. Hence, it clearly shows this fact that the conventional agricultural systems in achieving the human needs of food is relatively unsuccessful, yet, with some furthers adverse environmental effects. Thus, sustainable agriculture has been considered as the most effective solution for this matter by experts. Because of the roles and importance of agriculture in the economy and in employment of Jiroft County and due to the vegetables' place in consumers' health, this study has been accomplish with the aim of comparing the sustainable agricultural practices in onions, potatoes and tomatoes produced in Jiroft in 2008-2009 production year. For this purpose 197 farmers were selected throught the appropriate stratified random sampling from their population. The results showed that 52/3 percent of producers perform unsustainable and relatively unsustainable agricultural practices and only 31 and 16/7 percent of them are within the relatively sustainable and sustainable classes respectively. The results of multivariate analysis of variance show that potatoes farms are located in some more unsuitable circumstances than the onions and tomatoes farms. The results also showed that the causes of sustainability in agricultural operations of tomatoes producers compared with onions and potatoes producers is in their better management of weed control, cultivation and soil fertility. On the other hand superior sustainability of onions producers is in their pests and diseases control management as compared with that of potatoes producers.

Regarding to suitable tillage system achievement for wheat production in rotation with chickpea cultivation, five different tillage methods were examined during the 5 years (2004-08) in Dryland Agricultural Research Institute (DARI) of Maragheh with four replicates in randomized complete block design (RCBD). The five tillage treatments were T1= moldboard plow + roller, T2= chisel plow + roller, T3= cyclotiler, T4= sweep + roller and T5= no-tillage. Soil physical and chemical properties accompanied with wheat production were measured. Results obtained by statistical analysis showed that the treatments had significant effects on bulk density (BD) and soil pH. T1 (1.23 gr/cm3 in average) had most effect on decrease of soil compaction although; the differences were not significant compared with T4 and T3. T5 (1.34 gr/cm3 in average) had Maximum BD. T5 (7.39 in average) had minimum pH in compared with other treatments. The treatments had no significant in Organic mater (OC), but T5 and reduced tillage (T2 and T4) tended to increase the OC. The treatments had no significant differences in soil moisture. The results showed that decreased of BD, tended to increase soil moisture. The combine analysis showed that the treatments had no significant differences in grain yield. According to result and advantages of different tillage methods, T2 and T4 could be suggested instead of T1.

Each enterprise considering its structure, requires different types of management to achieve the goals. Management of farmlands mechanized agricultural systems is one of the important factors to succeed farmers. In this research, a model was developed to select agricultural machinery fleet, particularly in multicropping systems. The Model was a linear integer optimization model for minimization of costs and performed under LP-ILP (QSB) program. Raw data for three crops of wheat, barley and potato were obtained from the Ahyai Agriculture Complex located in Hamedan city, and related analyses were performed. Finally, according to the constraints of working periods, optimal required machinery set was calculated and proposed. This optimal machinery set supplied machinery requirements of farms and also minimized machinery costs.

Performance of grain harvesters is estimated by Threshing Power, losses fuel consumption. Grain loss is the most important of them. Total grain losses of combine harvesters in Iran is about 20% of production and sometimes higher. One of ways concern to loss reduction is separation of harvesting processes and providing a desire Mathematical Model for them by investing and measuring of important parameters in losses. Threshing is one of these processes which has more effect on combine performance. Threshing efficiency varies in reverse with threshing loss. It is desire to maximize threshing efficiency in threshing mechanism, because it will decrease the threshing losses and the load of separation mechanisms. Height of stem, feed rate, space between threshing drum and concave and rotational speed of threshing drum are operating factors which not only effect threshing efficiency but also combine loss. In order investigate the effect of mentioned parameters on threshing efficiency an experiment was conducted In 4×3×3 factorial pattern with completely randomize blocks design. Independent variables in these experiments were stem height, feed rate, clearance ratio and rotational speed of threshing cylinder. Threshing efficiency was considered as dependent variable. Analysis of variance showed that all variables had significant effect on threshing efficiency but interaction effects of them were not significant (P<0.01).Threshing efficiency increase when stem height, feed rate, and threshing clearance decreased. Also as rotational speed of cylinder increased, threshing efficiency increased. Multiple regression was used to express relation between dependent and independent parameters. The most compatible model for threshing of materials (y1) was as follow: y1=a0e(a1x1+a2x2+a3x3+a4x4) Which x1, x2, x3 and x4 were stem height, feed rate, threshing clearance rate and speed of threshing cylinder respectively and a0, a1, a2, a3 and a4 were constants.

To evaluate the effects  of biological nitrogen (Azotobacter) and plant density on quantitative and qualitative traits of anise, a field experiment was carried out with a factorial combination of deferent levels  of Azotobacter (0, 3, 6 Lit / ha) and plant density (50, 25 and 12.5 plants/m2) based on randomized complete block design with 3 replications. Analysis of variance showed the significant effect of biological nitrogen and plant density on plant height, leaf number, peduncle length, number of fertile umbellete/umbel, biomass, essential oil, seeds yield , harvest index of seed and essential oil. The means comparison indicated that the highest plant height and peduncle length were obtained from 50 p/m2 of plant density. Also the highest biomass yield (6319 kg/ha) and seed yield (1017 kg/ha) were obtained from 50 and 25 p/m2 of plant density with 6 Lit/ha of Azotobacter application, respectively. While, the highest yield of essential oil (130 kg/ha) was obtained from 3 lit/ha of Azotobacter and 25 p/m2 of plant density. The lowest yield of biomass, seeds and oil were obtained from 12.5 p/m2 of plant density and control treatment of nitrogen (0 l/ha of Azotobacter). These trends in yield led to highest amounts of seed and oil harvest index at 6 and 3 l/ha of Azotobacter application, respectively. These results showed the increasing essential oil production at relatively low nitrogen.

In order to study the effect of crop rotation and different systems of soil fertility on grain yield and quality of canola (Talayeh cultivar), an experiment was conducted at experimental farm of Agricultural Research Center of Sanandaj in 2008 - 2010 growing seasons. Experimental designs were arranged in split-split plots based on randomized complete blocks design with three replications. Main plot consisted three crop rotation, (R1): Chickpea, Sunflower, Wheat, Canola; (R2): Green manure, Chickpea, Green manure, Wheat, Green manure, Canola; (R3): Canola, Canola, Canola. Sub plots consisted of five strategies for obtaining the basal fertilizers requirement that included (N1): farm yard manure; (N2): compost; (N3): chemical fertilizers; (N4): farm yard manure + compost and (N5): farm yard manure + compost + chemical fertilizers; and control (N6). Sub-Sub plots consisted four levels of biofertilizers: (B1): Bacillus lentus and Pseudomonas putida; (B2): Trichoderma harzianum; (B3): Bacillus lentus and Pseudomonas putida & Trichoderma harzianum; and (B4): control, (without biofertilizers). Results showed that rotation, basal fertilizers, biofertilizers and interactions of them have significant effects on grain yield. The highest grain yield was obtained from R2N5B3 treatment, that organic and chemical fertilizers were co applied. Crop rotation, basal fertilizers, biofertilizers and interactions of them have a significant effect on leaf chlorophyll. The highest nitrogen content (38.9 mg/g) and least amount of (N/S) were obtained from N5B3 treatment. Crop rotation, basal fertilizers and biofertilizers have a significant effect on oil percent and oil yield.

To study the effect of deficit irrigation on cotton yield, determination of yield function and water use efficiency, an experiment was conducted based on randomized complete block design (RCBD) with four replications on cotton (Sahel variety) in BayeKola, Agricultural Research Station of Mazndaran Province during 2002 - 2003. Irrigation treatments based on 0, 25, 50, 75, 100 and 125% of water requirement,  affected cotton yield significantly (P<0.01). The highest and lowest cotton yield with 1679 and 3099 Kg/ha were obtained from I0 treatment (0% of water requirement) and I3 (75 % of water requirement), respectively; while the highest values of water use efficiency were belonged to I0 and I1 treatments. There was no yield reduction in I3 with 25% less water requirement. While cotton yield in I2 (with 50% water requirement) was decreased 15%, significantly as compared with I4 (100% water requirement). Thus, full irrigation is not necessary for cotton irrigation in Mazandaran province, and irrigation with 75% of water requirement could be sufficient.

Determination of physical properties of agricultural products is very important for optimization design of processing, planting and harvesting machines. Physical properties affect on the losses reducing and quality protection of products at going through of postharvesting process. At this study, the effect of grain moisture content on some physical properties of two varieties paddy grains (Sephidrod and Binam) was investigated. These properties included length, width, thickness, geometrical diameter, mathematical diameter, sphericity, thousand seed weight, bulk density, true volume and true density. The levels of grain moisture content were 10, 14, 18, 22% (w.b.). The results showed that with increasing of grain moisture contain, geometrical diameter, mathematical diameter, area, volume, thousand seed weight, bulk density and true density were increased significantly (p<1%). But true density was decreased. Also Sphericity no verified significantly.

This study carried out in RCBD with 6 treatments and 3 replication in dry land agricultural research institute during 4 years (2003-2007). In automn tillage treatments and in spring sowing of seeds were completed. Treatments were: T1= Sweep in fall + planting by seed drill in spring, T2= Removing stubble in fall + direct planting by seed drill in spring, T3= Semi-moldboard plow in fall + disk harrow and planting by seed drill in spring, T4= Chisel plow in fall + disk harrow and planting by seed drill in spring, T5= Fertilizer and seed broadcasting by hand and moldboard plow in spring, T6= Chisel plow in fall + fertilizer and seed broadcasting by hand and disk harrow in spring. The results showed that wet and dry forage yields were different among treatments, T4 with 5393 and 3190 kg/ha had the highest forage yield and T5 with 4643 and 2646 kg/ha had the lowest forage yield. This trend was abserved in stubble and grain yield T4 with 3245 and 1121 kg/ha had highest yield and T5 with 2749 and 707 kg/ha had lowest yield. The effect of year on wet and dry forage and grain yields was significantly different (1%) but the intraction of year on treatments was not significant. soil moisture was differ among treatments. moistuer comparison in 3 soil depths showed that T4 treatment was better than other treatments and had 24.90, 26.67 and 28.04% soil moisture and T6 treatment had 18.92, 19.18 and 20.87% soil moisture.

Salinity affects the yield and quality of fruit crops as the result of modifying water and nutrient uptake. In split root system it may be possible to reduce the deleterious effect of salinity on the plant growth. Therefore, an experiment was conducted on strawberry (cv. Comarosa) with different concentration of NaCl (0, 30, 60 and 90 mM) in hydroponic system using a randomized complete blocks design. The whole root system was divided into two portions and either even or uneven salinity was applied. The treatments consist of 0:0(nutrient solution alone in both part of the root system), 0:30(one portion of the root system nutrient solution alone and other portion nutrient solution plus 30 mM NaCl) and respectively 0:60, 0:90, 30:30, 60:60 and 90:90 with four replications. The results showed that the increased salinity at two portions of the root systems reduced growth characteristics including fresh and dry weight of plants. However, when one portion of the root system supplied with salinity, the adverse effect of salinity was reduced. Maximum fresh and dry weight and length of fruits were observed in 0:0 and 0:30 treatments while in 90:90 treatment they were reduced. The plants grown with 90:90 died at the end of experiment. The yield and fresh weight of fruits was higher when one portion of root system supplied with solution salinity up to 60 mM. Salinity caused increasing of TSS and EC of fruit juice. The highest and lowest TSS was achieved in 90:90 and 0:0 treatments, respectively, but the total soluble solid (TSS), dry weight and longevity fruits were in 0:30 treatment higher than 0:0 treatment. It can be concluded that use of 0:30 treatments can improve quality of strawberry fruits without reducing yield.

In this research, we used downscaled data from ECHO-G General Circulation Models and A1 scenario to investigate the climate change impacts on apricot and almond growth and development in the period between 2010-2039. The main concern is freezing occurrence especially spring coming late and winter heavy freezings that would be limitation factors for the growth. The results of this research showed that, in average, the light and heavy coming late freezing occurrences date will be stopped 13 and 7 days earlier from long term averaging respectively. The occurrence frequency and coming late freezings will also be decreased relative to long term average in the three station including Mashhad, Torbat-e Heydariyeh and Sabzevar. The mapping base on critical temperature occurrence data and phenological stages for apricot and almond in the future period showed that the vast regions of Khorasan Razavi province especially Torbat Heydariyeh will be fall in the to dangerous region. Based on the obtained results of this research, Chenaran, Mashhad and Neyshaboor that are the main producing area of apricot will also be located in the dangerous region.